1. Field
The following description relates to a bulk acoustic wave resonator (BAWR)
2. Description of Related Art
A bulk acoustic wave resonator (BAWR) may operate through electrodes that are disposed on and/or below a piezoelectric layer. In response to a high frequency electric potential being applied to the electrodes, the piezoelectric layer may oscillate. As a result, the BAWR may function as a filter.
While the BAWR operates as a filter, a bandwidth of the BAWR may be proportional to an Acousto-electric coupling coefficient. The Acousto-electric coupling coefficient may be affected by a film characteristic of the electrodes and the piezoelectric layer. Therefore, to increase the bandwidth of the BAWR, a value of the Acousto-electric coupling coefficient needs to be increased. However, it is difficult to increase the value of the Acousto-electric coupling coefficient by improving a configuration and crystallizability of the film of the electrodes and the piezoelectric layer.
Therefore, there is a desire for a new approach to improve a bandwidth of a BAWR.